Doosan DX520LC-9C Fault Code E000656-13: Complete Diagnostic Guide

What is Doosan DX520LC-9C Fault Code E000656-13?

Fault Code E000656-13 indicates a "Swing Motor Solenoid Valve Circuit - Current Below Normal" error in the Doosan DX520LC-9C excavator's electrical system. This code is triggered when the Electronic Control Module (ECM) detects abnormally low current flowing through the swing motor solenoid valve circuit, typically below the manufacturer's specified threshold of approximately 0.5 amps during activation.

This fault directly affects the excavator's swing function control system, which regulates the upper structure's rotation. The solenoid valve controls hydraulic flow to the swing motor, and when the ECM cannot maintain proper electrical current to this valve, it compromises precise swing control and overall machine productivity. For the DX520LC-9C model, this is particularly critical as the advanced hydraulic system relies on precise electronic signals for optimal fuel efficiency and operational smoothness.

Common Symptoms

When Code E000656-13 is active, operators typically experience:

• Intermittent or complete loss of swing function, with the upper structure failing to rotate or responding sluggishly
• Swing motor warning light illuminated on the instrument cluster, often accompanied by an audible alarm
• Reduced swing speed or jerky, inconsistent rotation even when the valve partially functions
• ECM derate mode activation in some cases, limiting overall machine performance to protect hydraulic components
• Error message displayed on the monitor panel specifically referencing swing system malfunction

Potential Causes

The most common technical causes for this fault code in used DX520LC-9C excavators include:

• Open circuit or broken wiring in the harness between the ECM and swing solenoid valve, particularly at known flex points near the swing bearing
• Corroded or loose electrical connectors at the solenoid valve or ECM terminals, common in machines with high operating hours
• Failed swing motor solenoid valve coil, resulting from internal winding breakdown or moisture intrusion
• Damaged ECM output driver circuit, though less common, can prevent proper current delivery
• Harness chafing or insulation wear at the center joint area where cables route through the rotating assembly
• Poor ground connections at the swing motor mounting points, creating high resistance paths

How to Troubleshoot and Fix Code E000656-13

Step 1: Visual Inspection and Connector Check

Begin by inspecting the swing motor solenoid valve connector for corrosion, bent pins, or moisture. On used excavators, this connector often experiences environmental exposure. Disconnect and clean with electrical contact cleaner, then check for physical damage. Inspect the wiring harness routing from the ECM through the center joint, looking specifically for abrasion points where cables contact metal edges.

Step 2: Electrical Testing with Multimeter

Using a digital multimeter (DMM), measure the solenoid valve coil resistance. Disconnect the valve connector and test across the solenoid terminals. Typical specification is 3-7 ohms at room temperature. A reading of infinite resistance indicates an open coil requiring valve replacement. Next, check for continuity in the harness by testing from the ECM connector (valve control output pin) to the solenoid connector with the harness disconnected at both ends. Any reading above 2 ohms suggests damaged wiring.

Step 3: Current Draw and ECM Output Testing

Reconnect the system and use a clamp ammeter or DMM in series to measure actual current draw when the swing function is activated. Compare against Doosan specifications (typically 0.8-1.2 amps during energization). If current is below normal but resistance tested good, suspect ECM driver failure. Use Doosan DMS diagnostic software to command the solenoid valve manually and monitor real-time current output from the ECM.

Step 4: Harness and Ground Verification

For used excavators, pay special attention to harness wear at the center joint. Remove protective covers and physically inspect for wire-to-wire shorts or ground faults. Test ground circuit integrity by measuring voltage drop between the solenoid valve ground and battery negative during operation—readings above 0.5 volts indicate poor grounding requiring cleaning or cable replacement.

---

Disclaimer: This guide provides general diagnostic procedures for informational purposes. Always consult the official Doosan service manual for your specific machine serial number and software version. Complex electrical repairs should be performed by certified technicians with proper diagnostic equipment to avoid further damage or safety hazards.